Aralen (generic: chloroquine) is a prescription medication used to prevent and treat malaria. It is also used to treat amebiasis (an infection caused by the parasite Entamoeba histolytica). This medication belongs to a group of drugs called antimalarials and amebicides. The exact way it works to kill parasites is unknown.

Aralen comes in tablet form. Take this medication with food to minimize stomach upset. Aralen is taken once or twice a day, unless it is used for the prevention of malaria, in which case it is taken once a week beginning 2 weeks prior to traveling to an area where malaria is common.

Common side effects include headache, loss of appetite, diarrhea, and upset stomach.